Switch lock



SWITCH LOCK Filed Oct. 1. 1924 l, l NTOR Patented Apr. 12, 1927.

UNITED` STATES Parana* ortica.

v CHARLESL. SI'OEL'LZLEN,V OF ERIE,V PENNSYLVANIA, ASSIGNOR TO BURKE ELECTRIC Y COMPANYQKA CORPORATION OF PENNSYLVANIA.

' SWITCH Loox.

Application filed October l,l 1924. Serial No. 740,973.

This invention relates to switches and particularly to switches which are subjected to heavy overloads tending to blow open the switch and break the circuit. Such unin- 6 tended breaking of the circuit is often attended with dangerous arcing and violent surging of the line.

The object of this invention is to provide a switch lock which will hold the switch l closed against accidental opening and at the same time will not interfere with the intentional opening and closing of the switch. A. further object of the invention is to provide such a switch lock which may be `'readily attached to installed switches without dismantling or machine work.

In the accompanying drawings illustrating the invention.

Fig. 1 is an elevational side view of a switch lock embodying the invention, and

v Fig. 2 is a sectional view on the line 2 2 of Fig. 1.

In the specific embodiment of the invention shown in the drawings a blade switch has a stationary member 3 carried, for

instance, by a wall bracket 4 ror supported in any desired manner. The movable switch part is designated 5, only the upper end being shown. the lower end being mounted on a pivot in the usual manner so that the blades 5 move into and out of contact with the stationary leaves 3 along the line of the are indicated by dotted line 6. This may be considered to exemplify the usual type of blade switch.

To hold this switch against unintentional opening the lock parts are carried by the stationary and movable parts of the switch. On the base of the stationarv part 3 are clamped the horizontal clamping bars 7. 8 drawn together by bolts 9 to grip the switch base between them. The. lower clamping bar 8 carries the downwardly proiecting bracket arms 10 which at their lower ends support the horizontally extending locking pin 11 thus held in stationary position with relation to the switch.

Fastened at the movable switch member 5 are the side plates 12, 13 tightly clamped in place by bolts 14 as shown; each plate 12, 13 carries a stubl shaft 15 upon which is pivoted alocking pawl 16 on each side. Each pawl16 is resiliently drawn downward by a spring 17 so as to hold the hook 18 of the'pawl in locking engagement with the pin 11 and thus prevent the switch 5 from opening.

To release the pawls from locking engage .ment Vand open the switch 5 a yoke shaped member 20 is provided having each of its Vside portions pivoted upon the stub shafts 15 and normally resting with its pins 21 against the stops 22 of the pawls 16, the springs 17 being sufficiently strong to support the weight of the yoke and its connected parts without yielding. The yoke 2() lcarries a .handle or a. loop 23Kas shown in the drawings adapted to be reached by a suitable instrument and drawn downward and outward to release and open the switch. During this opening movement pivotal movement of the voke 2O around the axis of the stub shafts 15 tips the hook ends 18 ot the pawls 16 upward by the pressure of the pins 21 against the stops 22 so as to releaseY the hooks 18 :trom the ends of the locking pin 11. This pivotal' movement of the yoke 20 and pawls 16 is stopped by engagement of the stops 25 of the pawls against the pins 26 of the side plates 12, 13. Thereupon a further pull on the loop 23 will pull open the switch member 5.

To close the switch the loop 23 is pushed upward so as to pivot the hook 2O clockwise around the'stub shafts 15V and this brings the stops 27 of the yoke against the pins 26 of the side plates 12. 13 so that the yoke becomes rigid with these side plates. Further upward pressure on the loop 23 will close the switch. the hook ends 18 of the pawls 16 riding up over the ends of the pin 11 bv engagement of the inclined surfaces 28 with said pin. The spring 17 then draws the Dawls down into locking engagement with the pin 11 as shown. Y

The switch lock of this invention is simple in form and easily adapted to various forms of switches. and readily attached to the switch withoutremoving the same and without expensive machine work. It is only necessary to clamp one part on the stationary part of the switch and the other part on the movable part of the switch. There is no interference with the cooperating stationary and movable parts and no alteration of these parts. The switch lock is conveniently positioned between the switch pivot and the contact area and there is no interference whatever with the cooperating contact making portions of the switch.

I claim:

l. The combination with a switch comprising a stationary and a movable part, a clamp attached to the stationary part and carryiinr a stationary lockinrr member comprisme` a locking pin, the ends ot which extend bevond the stationary part, a clamp fastened to the movable member, a spring pressed movable member comprising two eonmlementary plates carried bv said second mentioned clamp and cooperating with the ends ot the stationary lockingr pin to loclr the switch in closed position, and an operating member carried by said second mentioned clamp and engaging said movable member to release said lock and permit the switch to be opened.

2. The combination with a switch comprising a stationary and a movable part, a

stationary locking member comprising a locking;r pin, a clampingr means fastened to the movable member, a sprintf pressed lool:- ing member carried by said clamping: means eonnn-isinfr two riaivl members adapted to roommate with said locking pin to lock the switch in closed position. and an operatingY member carried bv said clamping` means and engaging; said niovable lockingr member to release said lock when moved in one direction to open the switch and releasing said movable member it'or locking;- action when moved in the opposite direction.

il. The con'ibination with a switch comprising a stationary and a movable part, a clamp attached to the stationary part and carrying a stationary lockingF member, a clamp :fastened to the movable member, complementary springl pressed movable members pivoted on stnb shafts carried by the said second mentioned clamp and cooperating with the stationary locking' member to loeli the switch in closed position, and an operatingr yolte men'lber `pivoted to said stab sllalts and engaging said movable members to release said lock and permit the switch to be opened.

at. The combination with a switch comprisinga stationary and a movable part, a stationary locking` member comprising a locking pin extending' bevond the stationary part, a clamping' means removably 'fastened to the movable member comprising connile mentary plates havingr stab shafts, a spring pressed locking member comprisinleV complementary members pivoted on said stab shafts, and an operating.;` yoke member piv oted on said stub shafts andengraging said complementarv members to release said lock` when moved in one direction to open the switch and releasing said movable member tor locking action when moved in the opposite direction.

The combination with a switch comprismer a stationary and a movable part, a stationary locking member, a. clamping means comprising tivo connilementary plates adapted to clamp the movable member therebetween. a spring; pressed locking member carried'by said clamping means, and an operating member carried by saidclamping means and engaging said movablelookingr member to release said lock when moved in one direction to open the switch and releasinelf said movable member ,for locking action when moved in the opposite direction.

CHARLES L; STOELTZLEN. 

